Circuit interrupter



Aug-J7, 1926. 1,596,417

0. H. ESCHHOLZ El AL CIRCUIT INTERRUPTER Filed Augusi; 22, 1922 cm, H. m, 2 if, if M. Chargs H Wagner Patented Aug. 17, 1926.

UNITED STATES PATENT; OFFICE- OTTO H. EBGEHOLZ, OI WILKINSB ITRG, AN D CHARLES F.

WAGNER, or PITTSBURGH,

mSYLVANIA, ASSIGNOBS TO WESTINGHOUSE-ELECTRIC AND MANUFACTURING- COHPANY, A CORPORATION OF PENNSYLVANIA.

cincun mrannur'rna.

Application filed August as, 1922. Serial no. 633,563.

to form arcs across, the main contact mem bers at their points offinal engagement. This action occurs ecause of the relatively high inductance of the arcing tip path and results in erosion of the surfaces of the main contact members. 1

In the usual design of arcing tip and main contact circuits, ,the materials used in, and the proportions of the former are such .that the arcing tip circuit has an inherent 1y high indu'ctancecompared to that of the circuit through the main contact members; This higher inductance sometimes results in a perceptible delay in the transfer of current flow from the main contact members to the arcing tip circuit. i I

Our .invention has for its object the provision .of means for facilitating the transfer of an are from the main contactmemhere to the arcing tips. 80-

Figure l is a viewshowing the manner in which our invention may be applied to a circuit breaker, and

Figs. 2 and 3 show embodiments of our M invention. I a

Only so much of a circuit breaker is shown as 'i's"necessary"to explain our invention. A lifting rod 4 carries the usual bridging member 5 that is provided with a brush 0 6 andcarries movable arcing tips 7 and 8 that are bi asedupwardly into engagement with stationary arcing tips 9 and 10, res tivelyin the ,manner well known to skilled in devices of this character.

The brush 6 is provided with loops 11,- of magnetic material, and cd-operates with stationary contact'member's 12. Upon the separation of the brush 6 fromthe stationary contact members 12 the establishment of current flow across the arcing tips is de- "layed and arcs tend to form across those points of the main contact members last in engagement. By providing. loops .11 of As shown in the accompanying drawing,

steel, or other magnetic material, the inductance of the brush member is increased to a value slightly greater than that of the arcing-tip circuit, thereby rendering that flow and the diversion of current from the brush 6 to the arcing tip circuit, thus materially reducing the tendency to maintain current flow through the main contacts, when separating the bridging member 6 from the contact members 12.

The operation of the device of Fig. 2 is substantially the sameas that of Fig. 1, a brush 12 serving as the stationary contact member, and a bridging member 6 serving as the movable contact member. An in- .ductance member llfunctions inthe same manner as the member 11 of Fig. 1. r Fig. 3 shows still another modification of our inventionx In this form, the stationary contact member 14 is provided with an arc ing tip 15 which co-operates with amovable arcing tip 16 that is yieldingly supportedupon the bridgin member 17 which car ries the brush mem er 18,-that co-operates with .the stationary contact member 14. Instead of providing a loop about the bridging member 18 for increasing the in ductance thereof, We intersperse strips of steel, 19, 20, 21, 22 and 23, between the copper laminations of the bridging member 18.; These steel inserts not only produce a reaccelerating circuit less resistant to current" active effect, but cause a more uniform distribution of the cun'ent throughout the I brush. 1

In conductors of this character, a rapidly changing current tends to concentrate attheir perimeten, By maklng the inserts; 22

and 23 longer'thanthe intermediate in-' serts 19, 20 and-21, the inductance at the perimeter is greater thanat the middle, so that a substantially uniform distribution of the brush 18 is efl'ecte I ency towards the formation of arcsacross the. main contact members is reduced, both byreason" of'the uniform distribution of,

currentthroughout the contact member and '95 urrent throu out the body of the- 5. .Therefore, the tendby the inductance secured through the use of themagnetizable inserts 19, 20, '21, 22

and 23. p r

The loops 11 and 11, also tendto efiect a more umform distribution of the current in the brush members, particularly if placed close to the ends of the contact members as shown in Fig. 2.

Various changes in detail and eneral arrangement may be made without ileparting from the spirit and scope of the invention, as defined in the accompanying claims.

We claim as our invention:

1. The combination with two relatively movable main contact members and a pair of relatively movable auxiliary contact members, of means for increasing the inductance of one of the main contact members.

2. The combination with two relatively movable main contact members and a pair of relatively movable auxiliary contact members, of means for effecting a substantially uniform distribution of current in one of the main contact members.

3. The combination with two auxiliary conducting members, of two relatively movable main conducting members, one of which is provided with means for increasing the inductance of the circuit therethrough.

4. The combination with a pair of arcing tips, of two relatively movable. main contact members, one of which is provided with a loop of magnetic material.

5. The combination with a pair of arcing tips, of two relatively movable main contact members, one of which is provided with a magnetizable portion for increasing the inductance thereof.

6. The combination with co-operating arcing tips, of two relatively movable contact members, and inductive means carried by one of said contact members for facilitating the transfer of current flow from the said contact members to the arcing tips.

7. The combination with co-operating arcing tips, of tworelatively movable contact members, and an inductive member associated with one of the said contact members for facilitating the transfer of current flow from the said contact members to the arcing tips.

8. The combination with co-operating arcing tips, of two relatively movable contact members, and means for increasing the inductance of one of the said contact members, to facilitate the transfer of current flow from the said contact members to the arcing tips. t

9. The combination with an auxiliary conductin circuit, of a main circuit having a pair 0 conducting terminals, one of which is-provided with means for increasing the inductance thereof.

10. A circuit-interrupting device comprising means for establishing a main currentcarrying path of relatively low impedance, means for providing an auxiliary current path of relatively high impedance, the current from the main path being diverted to said auxiliary path 11 on opening said interrupter, and means or increasing the impedance of the main path to the development of a current therethrough to a value comparable to the impedance of said auxiliary path.

11. A circuit-interrupting device comprising means for establishment a main currentcarrying path of relatively low impedance, means or providing an auxiliary current path of relatively high impedance, the current from the main path being diverted to said auxiliary path upon opening said' interupter, and means for increasing the impedance of the main path to facilitate the di-- version of current from the said main path to the said auxiliary path.

In testimony whereof, we have hereunto subscribed our names this 8th day of August, 1922.

' OTTO H. ESCHHOLZ.

CHARLES F. WAGNER. 

